42,772 articles
Lava tube
A lava tube, also known as a lava tunnel or pyroduct, is a cave formed when lava's surface hardens into a roof and the molten interior drains away.
Lavalier microphone
A lavalier microphone, also known as a lapel mic or lav, is a small microphone clipped to clothing near the chest, leaving hands and camera frame free.
Lavender (color)
Lavender is a pale bluish purple color named for the flowers of the lavender plant, recorded as a color term from 1840 and defined in web standards as hex #e6e6fa.
Law of averages
The law of averages is an informal, non-mathematical phrase claiming random outcomes even out over time; probability theory rejects its short-run version as the gambler's fallacy.
Law of cosines
The law of cosines, also called the cosine rule, is a Euclidean geometry theorem relating a triangle's sides to one angle, generalizing the Pythagorean theorem.
Law of definite proportions
The law of definite proportions, or law of constant composition, states that a chemical compound always contains its elements in the same proportions by mass regardless of source, as formulated by Joseph Louis Proust.
Law of excluded middle
The law of excluded middle (tertium non datur) is the classical logic principle that every proposition is either true or false, rejected in intuitionistic logic.
Law of large numbers
The law of large numbers is a theorem of probability theory stating that the average of many independent random variables converges to their expected value.
Law of mass action
The law of mass action, also called the Guldberg-Waage law, is a chemical principle stating that reaction rates depend on reactant concentrations, proposed in 1864 by Norwegian chemists Cato Guldberg and Peter Waage.
Law of multiple proportions
The law of multiple proportions, or law of simple multiple proportions, is a chemistry rule stating that masses combining with a fixed mass form simple whole-number ratios, formulated by John Dalton.
Law of noncontradiction
The law of noncontradiction, also called the principle of non-contradiction, is the logical principle that a proposition and its negation cannot both be true at the same time.
Law of reflection
The law of reflection states that the angle of reflection equals the angle of incidence, both measured from the normal, with incident ray, reflected ray, and normal coplanar.
Law of sines
The law of sines, also called the sine rule, states that in any triangle each side divided by the sine of its opposite angle gives the same value.
Law of the iterated logarithm
The law of the iterated logarithm (LIL) is a probability theorem giving the exact envelope, of order sqrt(2n log log n), that random-walk fluctuations touch infinitely often, first proved by Khinchin in 1924.
Law of the unconscious statistician
The law of the unconscious statistician (LOTUS) is a theorem of probability theory stating that the expected value of g(X) can be computed directly from the distribution of X, without first deriving the distribution of g(X).
Law of the wall
The law of the wall, also called the logarithmic law of the wall, is an empirical relation in fluid mechanics stating that velocity in turbulent flow near a wall varies as the logarithm of distance.
Law of total expectation
The law of total expectation, also called the law of iterated expectations or tower property, states that a random variable's expected value is the probability-weighted average of conditional expectations.
Law of total probability
The law of total probability, also called the total probability theorem, expresses an event's probability as a weighted sum of its conditional probabilities over a partition of the sample space.
Law of total variance
The law of total variance, also called the variance decomposition formula or Eve's law, states Var(Y) = E[Var(Y|X)] + Var(E[Y|X]), splitting variance into explained and unexplained parts.
Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory (Berkeley Lab) is a Department of Energy national laboratory in Berkeley, California, managed by the University of California. Ernest O. Lawrence founded it in 1931 around his cyclotron.
Lawrence Bragg
Lawrence Bragg, also known as William Lawrence Bragg, was an Australian-born British physicist and X-ray crystallographer who shared the 1915 Nobel Prize in Physics with his father, William Henry Bragg.
Lawrence C. Evans
Lawrence C. Evans, born 1949, is an American mathematician at UC Berkeley known for nonlinear partial differential equations and his graduate textbook Partial Differential Equations.
Lawrence D. Brown
Lawrence D. Brown (1940–2018) was an American statistician, Miers Busch Professor at Wharton, known for decision theory, admissibility of estimators, and his 1996 nonparametric equivalence paper.
Lawrence F. Dahl
Lawrence F. Dahl (1929–2021) was an American inorganic chemist at the University of Wisconsin–Madison who determined the X-ray structures of transition-metal cluster compounds, from simple carbonyls to record palladium clusters.
Lawrence Grossman
Lawrence Grossman, born 1946 in Toronto, is a cosmochemist at the University of Chicago known for calculating mineral condensation sequences and showing CAIs are the Solar System's oldest solids.
Lawrence H. Aller
Lawrence H. Aller (1913–2003) was an American astronomer who specialized in the chemical analysis of planetary nebulae and stellar atmospheres, and a UCLA professor from 1962.
Lawrence Joseph Henderson
Lawrence Joseph Henderson (1878–1942) was an American biochemist and physiologist at Harvard whose 1908 blood-buffering formula became the Henderson–Hasselbalch equation, and who wrote The Fitness of the Environment (1913).
Lawrence M. Krauss
Lawrence M. Krauss is a theoretical physicist and cosmologist who taught at Yale, Case Western Reserve, and Arizona State, predicted dark energy in 1995, and wrote A Universe from Nothing.
Lawrence M. Wein
Lawrence M. Wein is an American operations research scientist, the Jeffrey S. Skoll Professor Emeritus at Stanford, elected to the National Academy of Engineering in 2009, known for biodefense and health-care models.
Lawrence O. Brockway
Lawrence O. Brockway (Lawrence Olin Brockway, 1907–1979) was an American physical chemist who established gas-phase electron diffraction for determining molecular structures, first as a doctoral student of Linus Pauling at Caltech.